Samsung has kept the same 5,000 mAh battery in its Galaxy S Ultra models for six years, but the Galaxy S27 Ultra could finally get a new kind of battery. A new leak claims Samsung is actively testing silicon-carbon batteries for its flagship phone.The blog Schrodinger Intel posted that Samsung is targeting next year to try silicon-carbon batteries. It's a big change, even as Samsung has managed to eke out incremental battery life increases with the lithium-ion batteries it currently uses. Most of those upgrades are software-optimized, not physical.In February, Sung-Hoon Moon, Samsung's executive VP and head of smartphone R&D,…